Mineral piercing apparatus



March 16, 1965 J, w, R055 MINERAL PIERCING APPARATUS Filed Dec. 8, 1961 INVENTOR JOHN W. ROSS B) 0.13 am ATTORNEY United States Patent Ofiice 3,173,499 MINERAL PIERCING ANPARATUS John W. Ross, Toronto, @ntario, (Ianada, assignor to Union Carbide Canada Limited, a corporation of Canada Fiied Dec. 8, 1961, Ser. No. 158,031 3 Ciaims. (Ci. 175--14) This invention relates to a novel mineral working apparatus and more particularly to a rock-piercing blowpipe.

There has been in use now for sometime a rock-piercing process wherein an intensely hot jet flame produced by the combustion of oxygen and fuel is applied to the localized area of the rock to be pierced. This process is completely described in US. Patent 2,286,191 and US. Patent 2,286,192, issued June 16, 1942.

Present jet-piercing practices require large volumes of oxygen. The production and storage of large quantities of oxygen at the drilling site is not always feasible, especially in the more remote area where minerals to be thermally worked are usually found. They also require water injection in the bore hole.

The primary objective of this invention is to provide an improved mineral piercing blowpipe which utilizes air and fuel instead of the present oxy-fuel burners. Another object is to provide a blowpipe which can be operated without water injection. Yet another object is to provide a blowpipe which can be operated with a closed cooling fluid system.

In addition to eliminating the production and storage problems associated with the use of oxygen the present blowpipe greatly improves the economies of the jetpiercing process.

In the drawings:

FIGURE 1 is a view of a cross-section of an exemplary apparatus according to the invention;

FIGURE 2 is a View of a section taken along the line 2-2 in FIGURE 1;

FIGURE 3 is a cross-sectional view of the fuel injection nozzle.

Referring to FIGURE 1, the present invention provides a novel rock-piercing blowpipe B comprising an outer casing 1 internally threaded at its rearward end 2 and externally threaded at its forward end 3. Positioned within the outer casing 1 is a cylindrical member 4. Such member 4- is radially spaced from the outer casing 1 to form an annular space therebetween. A sleeve 5 is located in the annular space to provide a coolant inlet passage 6 and a coolant outlet passage '7. The sleeve 5 extends beyond the externally threaded forward end 3 of casing 1 and seats against a shoulder 8 in cap 9 which is threaded onto the forward end 3 of casing 1. The sleeve 5 has orifices 1b which provide communication between the inlet passage 6 and the outlet passage 7. A discharge nozzle 11 is carried by the cylindrical member 4 and extends through an orifice provided in the cap 9. A closure member 12 is threaded into the rearward end 2 of outer casing 1 and provides a means for closing off the space between casing 1 and cylindrical member 4. A bafiie member 13 is concentrically positioned in cylindrical member 4 and forms gas passage 14 therewith. A secondary air inlet 15 is provided in closure member 12 and communicate with passage 14 for providing air to the baffle 13. Mounted inside the baifle 13 toward the forward end thereof is an air injector 16. Such injector has a plurality of orifices 17 in a circular pattern thereof (see FIGURE 2) and is provided with a threaded center section for receiving a fuel injection nozzle 18. Nozzle 18 is an example of a nozzle suitable for liquid fuels such as kero- 3,173,499 Patented .Mar'. 1.6, 1965 sene. For gaseous fuels such as natural gas, propane, acetylene the nozzle type may be varied accordingly.

Referring to FIGURE 3, nozzle 18 has inlet passages 40 leading into chamber 41. From chamber 41 the liquid fuel passes through a helical groove 42 on member 43 and out the passage 44. Primary air is supplied to the injector 16 from inlet means 19 provided in closure member 12 and communicating with the inside of baffle member 13 through annular chamber 20. Fuel is supplied to the fuel injection nozzle 18 through a tube 21 extending from the back of the blowpipe B down to the rear of injector 16 and is threaded therein to provide a passage from said tube 21 to the fuel injection nozzle 18. The injector 16 and fuel nozzle 18 provide a back wall of a combsution chamber C which is further defined by the walls of the forward end of baffle 13 and cylindrical member 4. An electrical ignition system is provided adjacent the fuel nozzle 18 in the combustion chamber C. Such system as represented here may inciude a coil 22 which is connected through conduit 23 to a source of electrical energy. Such coil may be, for example, a high resistance wire or alternatively an electrode means for producing a high frequency spark discharge can be used.

The blowpipe of the invention is preferably provided with a closed circuit cooling system. A coolant such as water or water-glycol mixtures in cold weather operations is introduced through coolant inlet 24 down pas sage 6 through orifices 1%) up passage 7 and out the outlet 25 to a heat exchanger 26 to a reservoir 27. Coolant is then pumped by pump P from the reservoir 27 back into the blowpipe B.

In operation, primary air and fuel is supplied to the blowpipe B through passage 19 and tube 21 respectively. The fuel injection nozzle sprays the fuel into chamber C where it mixes with the primary air issuing from air injector 16 and is ignited by coil 22. Secondary air needed for proper completion of combustion or excess when required is introduced downstream of fuel n0zzle 18 through orifices 28 in bafile 13 from air passage 14. The flame then issues from nozzle 11 which may be either a straight bore or De Leval type if supersonic velocities are desired.

The air-fuel ratio preferably used is about 13:1 and produces a flame temperature of about 20003000 F. with sonic or supersonic velocities.

Table I shows data which gives an indication of the type results that can be obtained with the apparatus of the invention.

With the closed circuit cooling system of the invention there is no steam available to eject spellings from the bottom of the hole. However, the spallings are ejected because of the high thrust obtained due to the nitrogen content of the flame.

Although the principles of the invention have been described with reference to an exemplary apparatus, it is to be understood that modifications of the apparatus may be made Without departing from the spirit and scope of the invention. For instance, the blowpipe may be provided with means for directing a cooling fluid through the cap 9 to provide external cooling.

What is claimed is:

1. A blowpipe for thermally Working mineral bodies and the like comprising a cylindrical member having a forward end; a tubular bafile concentrically positioned Within and set back from the forward end of said cylindrical member; an air injector having a plurality of orifices positioned axially around the circumference thereof and being secured Within the said bafile; means for supplying primary air to said air injector; a fuel injection nozzle mounted on said air injector within the circumference of orifices on said air injector and extending into a combustion chamber closed at one end by said air injector and nozzle and defined by the wall of said hafile and said cylindrical member; means for supplying fuel to said fuel injection nozzle; means provided adjacent said fuel injection nozzle for internally igniting said fuel and air; means for supplying secondary air to said combustion chamber through said bafile; and a discharge nozzle carried by the forward end of said cylindrical member and communicating with said combustion chamber.

2. Apparatus according to claim 1 and including a plurality of coolant passages surrounding said cylindrical member and discharge nozzle.

3. Apparatus according to claim 1 provided with a coolant inlet and outlet passage substantially surrounding said cylindrical member and discharge nozzle and means connecting said inlet and outlet passage so as to continually recirculate said coolant through said passages.

References Cited in the file of this patent UNITED STATES PATENTS 1,379,179 Good May 24, 1921 2,436,002 Williams Feb. 17, 1948 2,725,929 Massier Dec. 6, 1955 2,794,620 Arnold et al June 4, 1957 2,796,118 Parker et al June 18, 1957 2,896,914 Ryan July 28, 1959 2,964,103 Ryder Dec. 13, 1960 2,990,877 Tramontini July 4, 1961 3,103,251 Browning Sept. 10, 1963 

1. A BLOWPIPE FOR THERMALLY WORKING MINERAL BODIES AND THE LIKE COMPRISING A CYLINDRICAL MEMBER HAVING A FORWARD END; A TUBULAR BAFFLE CONCENTRICALLY POSITIONED WITHIN AND SET BACK FROM THE FORWARD END OF SAID CYLINDRICAL MEMBER; AN AIR INJECTOR HAVING A PLURALITY OF ORIFICES POSITIONED AXIALLY AROUND THE CIRCUMFERENCE THEREOF AND BEING SECURED WITHIN THE SAID BAFFLE; MEANS FOR SUPPLYING PRIMARY AIR TO SAID AIR INJECTOR; A FUEL ININJECTION NOZZLE MOUNTED ON SAID AIR INJECTOR WITHIN THE CIRCUMFERENCE OF ORIFICES ON SAID AIR INJECTOR AND EXTENDING INTO A COMBUSTION CHAMBER CLOSED AT ONE END BY SAID AIR INJECTOR AND NOZZLE AND DEFINED BY THE WALL OF SAID BAFFLE AND SAID CYLINDRICAL MEMBER; MEANS FOR SUPPLYING FUEL TO SAID FUEL INJECTION NOZZLE; MEANS PROVIDED ADJACENT SAID FUEL INJECTION NOZZLE FOR INTERNALLY IGNITING SAID FUEL AND AIR; MEANS FOR SUPPLYING SECONDARY AIR TO SAID COMBUSTION CHAMBER THROUGH SAID BAFFLE; AND A DISCHARGE NOZZLE CARRIED BY THE FORWARD END OF SAID CYLINDRICAL MEMBER AND COMMUNICATING WITH SAID COMBUSTION CHAMBER. 